The present invention relates to an arrangement in a paper machine dryer section for spaces situated underneath the dryer section of the paper machine. Horizontal beams or equivalent are arranged above, or in the upper part of, the space underneath the dryer section in the paper machine hall and support the frame of the dryer section of the paper machine. The horizontal beams are supported by vertical beams. The dryer section is surrounded by a hood placed above the floor level of the paper machine hall. The hood surrounds the dryer section and confines the moist spaces of the dryer section in an interior of the hood. The present invention also relates to a dryer section including such an arrangement.
In the prior art, on the floor of the basement spaces situated underneath the dryer section of the paper machine, a broke conveyor is arranged to carry portions of the paper web that fall down from the dryer section, in the event of a break in the web, into as associated pulper. The paper falling down from the dryer section onto the broke conveyor completely occupies the basement space so that no other equipment can be placed there. Also, equipment is not usually placed in the basement spaces since the basement spaces are moist and hot. In the prior art, the basement spaces consist of a space substantially unified with, i.e., communicating with, the interior space of the hood placed on the dryer section above the floor level of the paper machine hall, so that in the basement spaces, there is substantially the same moist and hot atmosphere as in the interior space in the hood. Conventionally, the basement space is provided with a so-called basement hood, by whose means, together with the hood placed above the floor level, the moist and hot spaces of the dryer section are isolated from the paper machine hall and from the rest of the environment. In a manner in itself known, the hood spaces are provided with ventilation and heat-recovery means.
With the exception of the removal of the paper broke, in the prior art, the basement spaces placed underneath the dryer section mostly consist of unused and wasted space, which must, moreover, also be provided with the basement hood. Typically, the dimensions of the basement spaces for an average dryer section are about 5 m.times.10 m.times.80 m (about 4,000 cu.m.)
When dryer groups having a twin-wire draw are used in the dryer section in the manner known from the prior art, an upper portion of the basement space is needed for the runs of the loops of the lower drying wires and for the alignment rolls. In recent years, increasing use has been made of single-wire draw and, in connection with it, so-called normal groups, in which the drying cylinders are arranged in the upper row and the reversing suction rolls or cylinders are arranged in the lower row. In this case, the loops of the drying wires run above the drying groups and an increased amount of useless wasted space remains in the basement.
Further, in the prior art, it is usually one manufacturer that supplies the dryer section of the paper machine, and another supplier that constructs the basement space underneath the dryer section so that the overall construction of a paper machine hall is not always as easy and flawless as might be possible.
As known in the prior art, the hydraulic central units of the dryer section of the paper machine and related devices, such as the press section and the calender, are placed at the side of the paper machine hall. A corresponding arrangement is also used in respect of the means of circulation lubrication. These prior art arrangements involve the drawback that they require very long pipelines and/or fluid conduits to the hydraulic actuators and to the points of lubrication. It is a further drawback that, in their typical locations, the hydraulic central units and the lubrication units are relatively unprotected and susceptible of, e.g., impacts from trucks. The long pipelines also require due protection.